Wyniki wyszukiwania - Biblioteka Nauki

1

Swinie zyja powietrzem

100%

Czyrak A.

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nr 08

21

2

Competitive and non-competitive NMDA receptor antagonists induce c-Fos expression in the rat anterior, cingulate cortex

63%

Wedzony K. , Czyrak A.

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tom 47

|

nr 3

3

Dopamine D1-like receptors agonist SKF 38393 increases cFos expression in the paraventricular nucleus of the hypothalamus - impact of acute and chronic cocaine

51%

Chocyk A. , Czyrak A. , Wedzony K.

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nr 3

425-440

EN

The present study indicates that activation of dopamine D1-like receptors by administration of SKF 38393 leads to dose-dependent (doses: 5, 10 and 20 mg/kg) increases in the expression of cFos proteins in the rat paraventricular nucleus of the hypothalamus (PVN). This effect was abolished by administration of SCH 23390, a dopamine D1-like receptor antagonist (0.5 and 1 mg/kg, given 30 min before SKF 38393 - 10 mg/kg), suggesting that the apparent effect is specific for activation of dopamine D1-like receptors. Expression of cFos after SKF 38393 (10 mg/kg) was observed in some, but not all, CRF-immunoreactive neurons, as well as in small portion of oxytocin- but not vasopressin-immunoreactive neurons (double-immunofluorescence experiments). There were also certain populations of nuclei that showed expression of cFos but did not co-localize with the above markers. We also found that both acute and repeated (once daily for 5 consecutive days) exposure to cocaine (25 mg/kg) attenuated the induction of cFos expression triggered by SKF 38393 when administered 24 hours after single or the last dose of cocaine (25 mg/kg). Attenuation was observed at the same level after single and chronic exposure to cocaine, indicating a rapid functional down-regulation of dopamine D1-like receptors that are resistant to subsequent doses of cocaine. These data provide evidence for the functional role of dopamine D1-like receptors in the PVN and indicate a functional adaptation of dopamine D1-like receptors following a single dose of cocaine without further progression of adaptation or resistance of D1-like receptor-mediated genomic function in the course of repeated cocaine intake.

4

The impact of competitive and non-competitive NMDA receptor antagonists on dopaminergic neurotransmission in the rat ventral tegmental area and substantia nigra

51%

Wedzony K. , Czyrak A. , Mackowiak M. , Fijal K.

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nr 5

5

Cortical localization of dopamine D4 receptors in the rat brain - immunocytochemical study

45%

Wedzony K. , Chocyk A. , Mackowiak M. , Fijal K. , Czyrak A.

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nr 2

6

A comparison of psychotomimetic effects of MK-801 and CGP 40116 in behavioural paradigms

38%

Zajaczkowski W. , Chocyk A. , Fijal K. , Mackowiak M. , Czyrak A. , Wedzony K.

Acta Neurobiologiae Experimentalis

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1999

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tom 59

|

nr 3

7

Distribution of calbindin-D28k and parvalbumin immunoreactive neurones in the cerebral cortex of rats neonatally treated with competitive NMDA receptor antagonist.

38%

Fijal K. , Chocyk A. , Czyrak A. , Mackowiak M. , Zajaczkowski W. , Wedzony K.

Acta Neurobiologiae Experimentalis

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1999

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tom 59

|

nr 3

8

Prolonged corticosterone treatment alters biochemical and functional parameters of serotonergic neurotransmission associated with a 5-HT1A receptors

38%

Czyrak A. , Mackowiak A. , Fijal K. , Chocyk A. , Tokarski K. , Bijak M. , Wedzony K.

|

1997

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tom 57

|

nr 5

9

DOI, an agonist of 5-HT2A-2C serotonin receptor, alters the expression of cyclooxygenase-2 in the rat parietal cortex

38%

Mackowiak M. , Chocyk A. , Sanak M. , Czyrak A. , Fijal K. , Wedzony K.

|

nr 3

EN

The hallucinogenic effect of DOI, serotonin 5-HT2A/2C receptor agonist, is known to be associated with the activation of cortical 5-HT2 receptors. However, the effect of DOI on excitability of cortical neurons and their subsequent function is still not quite understood. Previous immunohistochemical studies using Fos proteins expression as a marker of neuronal activity showed the involvement of arachidonic acid cascade, particularly cyclooxygenase metabolic pathway, in DOI-induced Fos proteins expression in the rat parietal cortex. DOI increases arachidonic acid release which is transformed itself via acceleration of cyclooxygenase metabolic pathway to biologically active metabolites, such as prostaglandins and tromboxanes. Since cyclooxygenase-2 (COX-2) expression correlates with neuronal activity, it was of interest to investigate whether DOI is capable of influencing the level of COX-2 protein and mRNA expression in the rat parietal cortex. It was observed that neurons which were positive for 5-HT2A receptors showed constitutive COX-2 immunoreactivity. It was found further, that COX-2 protein level was increased at 1h, and returned to the control level at 3 and 6 h after DOI (5 mg/kg) administration. In contrast, DOI decreased the COX-2 mRNA expression at all tested time points (1h, 3h and 6h after DOI treatment). The obtained results further support the suggestion that COX-2 activation and possibly arachidonic acid metabolites generated by COX-2 may be considered as important mediators of functional responses generated by activation of cortical 5-HT2A/2C receptors.